SWITCHING POWER SOURCE, METHOD AND CONTROL CHIP FOR CONTROLLING THE SAME

摘要

A switching power source, a method and a control chip for controlling the same are provided. The switching power source includes: a filtering and rectifying module, connected with an AC power source and configured to filter and rectify an alternating current outputted from the AC power source to obtain a direct current; a control module, connected with the filtering and rectifying module and configured to obtain an amplitude of the alternating current from the direct current, to adjust a frequency of a control signal according to the amplitude, in which the control module decreases the frequency of the control signal continuously or intermittently when the amplitude increases, and to output the control signal, and a primary constant current circuit, connected with the control module and the filtering and rectifying module respectively, and configured to receive the control signal and to output a constant current according to the control signal.